Rare May snowstorm bringing heavy snows from Colorado to Wisconsin

"Not the typical May forecast." That's the lead-in for today's National Weather Service forecast discussion for Minneapolis, where Winter Storm Achilles is expected to bring 6 - 9" of snow by Thursday morning. Snowfall rates as high as 1 - 3" per hour may occur in snow bands in East Central Minnesota this afternoon, and an 8 - 10" swath of snowfall is expected from South Central Minnesota into East Central Minnesota and West Central Wisconsin. With ratios of snow to liquid water an exceptional 5:1 or even 4:1 (normal is 10:1), the wet, heavy snow will be capable of downing power lines and tree limbs. However, the ground is warm, and accumulation on roads will be less of a problem than for the usual storm of this magnitude. The storm has already brought 7.3" of snow to Cheyenne, Wyoming, and 12 - 14" to locations 10 - 15 miles to the WNW of Cheyenne. Cheyenne's greatest May snowstorm on record was 18.3" on May 5 - 6, 1978. Denver, Colorado is expected to get 3 - 6" of snow from the storm; Boulder, Colorado has already received 8" of snow, Fort Collings got up to 9", and up to 28" has fallen in the Northern Rocky Mountains of Colorado.

Figure 1. Snow plasters trees in Fort Collins, Colorado, on May 1, 2013. Up to 9" of snow has fallen on Fort Collins from the storm. Image credit: wunderphotographer pkkeya.

A historic May snowstorm for some locationsAccording to the Minnesota Climatology Working Group, the greatest May snowstorm in Minneapolis is 3" on May 20, 1892, so today's winter storm has the potential to be the greatest May snowstorm in city history.

On Thursday, after the cold front from Achilles passes through Topeka, Kansas, up to one inch of snow is forecast to fall. May 3, 1907 was the only measurable snowfall at Topeka on record (3.2") during the month of May!

Figure 2. Snow on a Deserted Street in Dawson, Minnesota in Lac Qui Parle County on May 20, 1892. The storm brought Minneapolis its greatest snowfall on record, 3.0". Image courtesy the Minnesota Historical Society.

Quoting FLWeatherFreak91: I think he is demonstrating humorous sarcasm. Lol. Are you drinking largo?

lol..its one habit i didnt seem to pick up in my lifetime..if i drank..oh 3 six packs in my entire lifetime thats alot...probably not even that much..somehow i never picked up liking the taste whatever...wish i did that with cigs too..didnt lol.

wow Local met on the weather said we got hit with the first low today..tomorrow we get hit with the 2nd low in the gulf tomorrow..and...we get hit fri-sat..with the THIRD low..thats now in miss/ala...geez.............he also said pinellas county..where i live is 5 inches below normal so far thats why we are in the red...now maybe with all this rain that ranking will lessen i hope.

Quoting MississippiWx:This is a really neat animation from the MCS/MCV that developed over the Gulf last night and moved into FL this morning and afternoon. It shows the lightning flashes caught on visible and the hi-res IR image of the complex. Very neat.

This is my hurricane landfall probability map for the 2013 Atlantic hurricane season (thanks to a friend for outlining the coastline). Given the long range pattern hinted at by models -- I posted the CFSv2's pattern forecast for September this morning, and Levi has posted some from the UKMET and other models over the past few weeks -- and analogues for this season, I believe the coastline from Charleston, SC to New York, NY, and from Slidell, LA to Panama City, FL are at most risk. Same for the Greater Antilles.

The Bahamas have a very high risk of seeing a hurricane strike, and so do the northern Lesser Antilles. Probably a moderate chance for the southern Lesser Antilles. Moderate for Bermuda, the Cape Verde Islands, and the Azores.

As has been stated, regardless of any probabilities given by myself or others, one should be prepared every season.

Quoting MississippiWx:This is a really neat animation from the MCS/MCV that developed over the Gulf last night and moved into FL this morning and afternoon. It shows the lightning flashes caught on visible and the hi-res IR image of the complex. Very neat.

This is a really neat animation from the MCS/MCV that developed over the Gulf last night and moved into FL this morning and afternoon. It shows the lightning flashes caught on visible and the hi-res IR image of the complex. Very neat.

I don't know why they still have Pinellas in the same color while Hillsborough improved significantly when much of Pinellas officially recorded the same amount as much of Hillsborough: 1 to 3 inches. I know my house which is between Largo and Clearwater back home recorded 1.24. Another inch today to add to that.

Seems as if the drought monitor is always a bit behind the times.

I dunno, do they have to perform some intricate ground hydrology measurements before the official data can be recorded, or do they just go by recorded rainfall? My guess is the latter, since the amount of rainfall alone does not necessarily determine drought levels.

That color-coded drought monitor always reminds me of the annual flu season outbreak map. By the time the official flu numbers come in from the CDC, they are already hopelessly out of date in real time. But still, the media will report a "major flu outbreak is underway" even though in fact the local epidemic may have ended weeks earlier. Same with drought reports it seems.

Well we know the rainfall is tropical like again when the radar estimate over Tampa international airport says they've had a "trace" of rain but Tampa international has reported more than a half inch in reality, LOL.

Quoting seminolesfan:I do understand what you are getting at... No profound statements to make on that point. :)

The lack of surface heating absolutely played a role.Keep in mind though; There is a reason the climatological rainy season starts when it does for Central FL(including Tampa). The band of westerlies HAS to move N of the area to allow the meso-thermodynamics of seabreeze collision to occur on a regular basis. Our rainy season is much more about balancing smaller scale features to force convection than large level forcings. Ya know what I mean?

Yeah I know what you mean and what you say is true, my point though was that its weird how there has been frequently some outcome in the sounding preventing precip potential repeatedly despite different patterns. However, I'm really referring to past events which started out looking promising but ended in rainfall completely dissipating. Today though was expected given the lack of surface heating. Still a decent day of showers and thunderstorms and beneficial rain. The region is really far from the actual low center so forcing from the upper low is limited so convection is driven mainly by heating.

Keep in mind though, yes its the dry season but a drought is still a drought. Technically, 2 to 3 inches of rain per month which is generally the dry season average for much of Florida is not that dry of an average for many other places. Yes Florida is a different climate with different soil so it needs more rain than maybe other places that do just fine and green with those averages. However, my point is that its not that plenty of potent squall lines and heavy rain haven't nailed the area in the past during the drier season, they just aren't quite as common.

It is definitely true though that the westerlies need to leave before we enter the true rainy season. This isn't the rainy season quite yet because we are still being heavily influenced by mid latitude systems, and as I said we can still get and do get heavy rain events outside of the rain season.

it looks like there is a flow of mud coming from the street across the driveway and partially engulfing the cars in the driveway. Sinkholes will cause homes to collapse in holes but won't partially collpase them and then fill them with flood water and mud.

That's the nature of vort lobes rotating around the circulation of upper lows. One begins to lose its punch, the next stronger.

Well, looking at the trench, I guess I'll have to reclassify it as an "Erosion Hole". ;)

Added: There must be something serious happening under that home as I see no exit for the water!!!

For all those who confide in the new streaming Lauderdale webcams: Another big cruiser is going to leave the harbour during heavy weather (cam 1, outdoor audio with thunder is on):http://portevergladeswebcam.com/

Quoting LargoFl:so far no wind to speak of but..alot of booming going on and steady rain here jedkins..so far its the GOOD rain..the soaking in kind..which we need alot of.

Yeah for sure. I'll be returning back to my Pinellas home from FSU on Friday, it will be nice to return back to improving conditions since my last visit on Spring Break in March when it was horribly dry.

Its not why they fall apart with the given circumstances that is strange, its why the given circumstances keep occurring repeatedly that is weird. I hope you understand what I'm getting at by saying so?

Actually though, the sounding being that way makes sense today given some of what happened. There was thick cloud cover from early on in the day so its likely warm air advection ended up being slightly stronger above the surface due to a lack of surface heating which probably led to that sounding being the way it is.

I do understand what you are getting at... No profound statements to make on that point. :)

The lack of surface heating absolutely played a role.Keep in mind though; There is a reason the climatological rainy season starts when it does for Central FL(including Tampa). The band of westerlies HAS to move far enough N of the area to allow the meso-thermodynamics of seabreeze collision to occur on a regular basis. Our rainy season is much more about balancing smaller scale features to force convection than large level forcings. Ya know what I mean?

it looks like there is a flow of mud coming from the street across the driveway and partially engulfing the cars in the driveway. Sinkholes will cause homes to collapse in holes but won't partially collpase them and then fill them with flood water and mud.

Quoting LargoFl:I am with you on that jedkins, my next door neighbor has his rain gauge and here by me he said it came out to be just a touch over 2 inches...i guess its WHERE the rain gauges are located huh..a sprinkle on my side of the street and pouring on the other side.

Well a lot of Pinellas did get heavy rain yesterday and is getting decent rains today. More than likely it may be that Pinellas was just worse off to start than Hillsborough.